Light sources in wide use in commercial and other premises contain two or more parallel fluorescent tubes, each generally two, four or eight feet in length. The fluorescent tubes are commonly supported by sheet metal housings or frames. Light output from the apparatus is commonly of low overall efficiency. A major contributing factor to the low efficiency of many existing light sources is that the housing or frame of the fluorescent tubes is constructed of sheet metal having a white painted or porcelain finish. As a result, an unnecessarily high proportion of the light emitted from the fluorescent tubes which impinges on the housing surfaces is absorbed, or diffusely reflected, rather than reflected out of the apparatus. By improving the design of the surfaces adjacent to the fluorescent tubes it is possible to increase the efficiency of the lighting apparatus so that one or more of the tubes may be removed with little or no loss in useful light output. By so doing, reduced energy consumption and lower costs will result.